We discuss the impact of fixed window increase rules on network utilization, fair resource allocation and overall transmission effort. We exploit the dynamics of adaptive additive increase as the strategy of choice for regulating transmission in accordance with the current level of contention. We show that, based on the additive increase rate of flows, a contention-oriented responsive strategy can be designed to (i) increase utilization under low-contention, (ii) reduce overhead and transmission effort under heavy loads, and (iii) maintain system capability to reach fairness.